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(800) 524-4161
(800) 524-4161
Retaining Wall Geogrid
SRW · Universal & 3–9 Series
Retaining Wall Geogrid
Tie the Wall Into the Soil.
High tensile geogrid fabric pinned between courses and extended back into the retained soil, so the wall and the earth behind it act as one mass instead of two.
- Four grades, uniaxial & biaxial
- Widths 3′ to 12′, rolls to 150′
- Free shipping · (800) 524-4161
- 4Grades stocked
- 3–12ftRoll widths
- 150ftLongest roll
Start Here
What Is Geogrid?
Geogrid is a lattice fabric — woven polyester with a polymer coating, or an extruded polymer sheet — laid horizontally in the backfill behind a retaining wall and pinned between the courses of block. It works by interlock. Aggregate placed over the grid drops partly through the apertures and keys into them, so the fill above and below can no longer move independently. That turns a layer of loose stone into something behaving like a solid block, and it ties the wall face structurally into the soil mass it is retaining.
Without retaining wall reinforcement, a wall is only as strong as its own weight and the friction between courses. With it, the wall and the retained earth resist together. That is the whole mechanism, and it is why geogrid retaining wall construction costs a fraction of what a comparable concrete structure would.
Geogrid is not geotextile. Geotextiles are fabrics — non-woven needle-punched or spun-bond, or woven from plastic fibres — and their job is separation, filtration and drainage. Geogrid is an open lattice whose job is tensile reinforcement. A retaining wall often needs both, doing different jobs in different places.
Choose a Grade
Which Geogrid Do I Need?
All four options below are stocked. Geogrid for retaining wall work is graded by strength, and the series number is that grade. Taller walls, heavier surcharge and more difficult soil all push you up the ladder. Roll width sets your embedment depth — how far the grid reaches back into the retained soil — so check width as well as grade.
Universal Series
General purpose
The entry grade, and what most residential walls use. Stocked 3′, 4′ and 6′ wide on 45′ and 50′ rolls.
Shop Universal
3-Series
Standard reinforcement
More tensile strength for greater exposed height, a surcharge above, or clay backfill. Widths to 12′, rolls to 150′.
Shop 3-Series
5–9 Series
High strength
The 5, 7 and 9 grades — tall walls, steep slopes, poor soils, engineered designs. Widths to 12′, rolls to 150′.
Shop 5–9 Series
Retaining Wall Fabric
Separation & filtration
Geotextile, not reinforcement. Keeps fines out of the drainage stone. Most walls need this as well as grid.
Shop Fabric
Grade selection on an engineered wall is the engineer's call, not ours — if you have a design, order to the specified long-term design strength. If you do not have one and the wall is over about 4 feet, get one.
Decision
When Is Stabilizing Grid Needed?
Two things decide it: what the wall is built from, and what soil it is holding back. The more massive the wall material, the less grid you need — a heavy limestone wall carries more of the load in its own weight than a light manufactured block does.
Clay soil behind the wallHighly recommended. Clay swells when wet and holds water, making it the hardest soil to retain.
6″ or 8″ split face limestone, exposed height over 24″Should be considered.
Manufactured block wall, 36″ to 48″ highThis is where grid is most desirable, depending on design and block size.
A slope at the base of the wallTake grid into consideration — the toe has less passive support.
Wall over 6 ft, 24″ or wider dense blockGrid should be used.
Surcharge above the wall — driveway, parking, structureGrid, and an engineered design.
Why It Matters
Why Retaining Walls Fail
Walls rarely fail because the block was wrong. They fail for three reasons, and geogrid addresses the second and third.
1
Inadequate drainage behind the wall
The most common cause by a wide margin. Moisture circulates, then freezes and thaws — sometimes daily through the cold season. With clay backfill, ice works deeper into the soil each cycle and pushes outward against the wall. Drainage stone and filtration fabric fix this; grid does not.
2
More soil than the wall can hold
The wall is asked to retain a mass it was never designed for. Grid transfers that load back into the soil itself rather than leaving the wall face to carry it alone.
3
Built too high with no reinforcement
Height without reinforcement is the classic novice failure — and it happens with landscapers who should know better, too. People spend thousands on a wall and then thousands more tearing it down to start again.
The economics are one-sided. Adding grid means some extra digging, backfilling and compacting. That is cheap set against demolishing a failed wall and rebuilding it — which is the alternative, and it is not rare.
Grid Patterns
Uniaxial, Biaxial and Triaxial Geogrid
The aperture pattern determines which direction the grid carries load. Always check the manufacturer's specification before you roll it out — orientation matters, and getting it backwards wastes the reinforcement.
Uniaxial
Mono-oriented
Stretched along the longitudinal direction, giving rectangular or elongated apertures. Stress transfers along one axis only, so strength is far higher in that direction. This is the pattern for retaining walls and steep slopes, where the load path is one way — back into the soil.
Biaxial
Bi-oriented
Stretched in both longitudinal and transverse directions, giving roughly square apertures and transferring stress equally both ways. Widely used in construction for that reason, and the usual choice under roads and base courses where load comes from every direction.
Triaxial
Newer pattern
Triangular or diamond apertures, stretched in all directions. The geometry distributes load radially rather than along one or two axes.
Manufacturing differs too. Woven grids are tightly woven polyester with a protective polymer coating. Bonded grids join two or more sets of strands at right angles. Extruded grids are polymer sheets punched and stretched into an integral structure — stronger, but considerably less flexible than woven.
Installation
How to Install Geogrid in a Retaining Wall
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1Excavate for reinforcement
Remove existing soil across the reinforcement zone so the grid gets its full embedment length. You need level, sound soil behind the wall units for each grid layer to bear on.
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2Cut to embedment depth
Cut sections from the roll to the specified embedment length. Roll out from the wall toward the embankment. Check the manufacturer's spec for whether your grid is uniaxial or biaxial — in most cases it runs perpendicular to the wall face.
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3Hook over the pins
Engage the grid on the wall unit pins for a positive connection between block and grid, and keep the grid within one inch of the wall face.
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4Pull taut and stake
Pull the pinned grid tight to remove loose folds, then stake the back edge before and during backfilling and compaction. Stakes can come out once the fill is placed. Butt additional sections edge to edge for continuous coverage across each layer.
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5Backfill in 8″ lifts
Place fill over the grid in 8-inch lifts. Get a minimum of 6 inches of reinforcement fill over the grid before any equipment drives on it — and never drive or turn directly on exposed grid, which damages it.
Why Specify It
Advantages of Geogrid Retaining Wall Reinforcement
Far cheaper than concrete
A reinforced segmental wall costs a fraction of a comparable poured concrete retaining structure.
Faster to build
No forming, no curing. Grid goes in as the wall goes up, in the same operation as backfilling.
Recovers usable land
Supporting a steep bank lets you use ground that would otherwise be unbuildable slope.
Conforms to uneven ground
It feels flimsy in the hand, and that flexibility is deliberate — it moulds to a subgrade that is never truly flat.
Better in seismic events
A reinforced soil mass moves with the ground rather than resisting it rigidly, so it is far less likely to fail outright.
Vegetation still establishes
Grid does not stop grass. Seed over it and the slope greens up as normal rather than staying bare dirt.
Questions
Geogrid FAQs
What does geogrid actually do in a retaining wall?
It ties the wall into the soil it retains. Laid horizontally in the backfill and pinned between courses, aggregate keys into its apertures so the fill can no longer move independently. The wall face and the retained earth then resist as one mass rather than the block carrying the load alone.
Do I need geogrid for my wall?
It depends on wall material and soil type. Clay backfill makes it highly recommended at almost any height. For 6″ or 8″ split face limestone, consider it above 24″ of exposed height. For manufactured block it is most desirable between 36″ and 48″. Over 6 feet, or with any surcharge above the wall, use it — and get an engineered design.
What is the difference between geogrid and geotextile?
Geogrid is an open lattice for tensile reinforcement. Geotextile is a fabric — woven or non-woven — for separation, filtration and drainage. They do different jobs, and most retaining walls need both: grid in the reinforcement zone, fabric behind the wall keeping fines out of the drainage stone.
Uniaxial or biaxial for a retaining wall?
Uniaxial is the pattern for walls and steep slopes, because the load path runs one way — back into the retained soil — and uniaxial concentrates its strength on that axis. Biaxial carries load equally in both directions and is the usual choice under roads and base courses. Always check the manufacturer's specification for the roll you have.
Which way do I roll it out?
From the wall toward the embankment, and in most cases perpendicular to the wall face. Check the spec sheet — orientation is what makes the reinforcement work, and rolling a uniaxial grid the wrong way wastes most of its strength.
How far back does the grid need to extend?
That is the embedment length, and it comes from the wall design rather than a rule of thumb — it scales with wall height and the loads above. Roll width is what limits it, which is why we stock widths from 3′ to 12′.
How much fill goes over the grid before I can drive on it?
A minimum of 6 inches of reinforcement fill. Place backfill in 8-inch lifts, and never drive or turn a vehicle directly on exposed grid — that causes excessive damage.
Can I overlap grid sections?
Sections are butted edge to edge, not overlapped, to give continuous coverage across each layer. Grid carries tension along its length; side-by-side sections each do their own work.
Is geogrid the same as gravel grid or geocell?
No. Geocell is a three-dimensional honeycomb that confines fill vertically — good for slope protection and drivable gravel surfaces. Geogrid is a flat two-dimensional lattice that reinforces in tension. Different products for different problems.
What does shipping cost?
Nothing — shipping is free on every order, across all grades and roll sizes.